Hi there experts,

I'm a welding student looking for some clarification on a certain clause in our API 1104 code book 21st edition Welding of Pipelines and Related Facilities. Specifically Clause 6 for qualification. More specifically is 6.7 in Retesting.
Our instructor gave us this question, "If a welder fails to pass the qualification test may the company allow that individual to retest." I answered the multiple choice question with the choice of "Yes with proof of subsequent training." The correct answer that was on the test was, "Yes, but only once without subsequent training."
I would like to know which answer would be right. And if some clarification to why which that choice would be better. If you have time a little better explanation of that section.

Thanks, Jax